Rheostat



Patented pr. l0, 1923.

UNITED STATES PAUL HARRIS, I0]? NEW YORK, N. Y.

1,450,919 .PATENT OFFICE.A ;4

RHEOSTAT.

Application 1aed my 15, 1922'. serial No. 575,154.A

To a7] whom it may con-cern.:

Be it knownlthat l, PAUL Hannis, a citizen of the United States, and a resident of' the city, county, and State of New York, have inventeda new and useful Improvement, in Rheostats, of'which the followingr is a specification.

The object of my invention is to provide a rheostat which may be used for any suitable purpose as for use in connection with storage batteries for wireless apparatus, and the object of this invention is to provide an instrument which will be free from self' induction and give an easily ascertained and correct reading both as to the resistance in the circuit and the current flowing through the same, and also will permit a properregulation of this circuit. This and other objects are accomplished by my invention, one embodiment of which is hereinafter more particularly set forth.

For a more detailed description of my invention, reference is to be had to the accompanying drawings, forming a part hereof, in which- Figure 1 is a front elevation of a panel board provided with my improvement.

Figure 2 is a sectional view taken on the line 2-2 of Figure 1, looking in the direction of the arrows.

Figure 3 is a rear elevation of the struc-n ture shown in Figures 1 and 2.

Figures 4 and 5 are sectional views, Flgure 4 being taken on the line 44 of Figure. 42, looking in the direction of the arrows,

and Figure 5 being taken parallel therewith' and near thereto.

Throughout the various views of the drawings, simila`r reference characters designate similar parts.

My improved instrument 20 is applied to a panel board 21 or other suitable support, of the conventional kind and it consists of a dial 22 fixed to said board, a handle 23 with a spindle 24 fixed in this handle and passing through the center of the board and `journaled in a spool 25 which is fixed to the panel board 21 by means of screws 26, or any other suitable means. The spool 25 has two threads extending in the same direction and runningr with the same pitch for a purpose that will appear below. The spindle 24 is held in position by means of suitable nuts 27, one at the top and one at the bottom, and connected washers 28, and between the nut 27 and washer 28 at the bottom is fixed a bracket 29 with a slotted arm 30 in which is slidably mounted a contact 31 which has two fingers one ot' which extends into one groove and the other of' which extends into an adjacent groove, as shown. These fingers are guided by these grooves when the bracket 2S) is shifted.

The spool 25 has two wires 32 and which are secured in the end of the spool which is remote from the p anel board 21, as by plugs 34 or other securing means, in suitable openings, and the other ends of these wires are secured to the screws 26 which also have secured thereto the bars or conductors 35 and 36 which run to the binding posts 37 and 38 and are connected thereto by any suitable means, as by screws 39. It will bev understood that the spool 25 insulates the wires 32 and 33 from each other and that these two wires arc connected by the ngers 31 which are slidably mounted in the arm 30, and as the handle 23 is turned these fingers ride on these two wires and so connect them that more or less of the wires are in circuit, the current going in one direction through one wire and in the opposite direction through the adjacent wire so that under no circumstances can there be any self induction. c

The dial 22 has a spiral groove 4() which engages the bent end of a slidably mounted and slotted bar 41, this bar being carried about the spindle 24 and having a slot 42 which engages two pins-43 which are fixed in the handle 23, as shown in Figure 2, so that as this handle is turned the bar 41 will slide in and out. The groove 4() carries suitable numbers beginning with 1 and ending with any other number, as 12, as may be desired, and each number represents an ohm resistance, and the wires 32 and 33 on the spool 25 are calibrated accordingly so that when theV arm 41V has its end at any one of the numbers th resistance interposed by the rheostat will be as represented by the intersection of the end of this arm with the point of the spiral indicated by the number. This arm also has a numbeof marks corresponding to the amount of resistance in the circuit which indicate Athe value of the current passing through the resistance of the rheollo Where the bar 41 emerges from under the handle 23. This bar may be changed so as to read according to the potential of the battery'or other power supplying means.

In View of the foregoing, thev use of my improved rheostat will be readily understood. Assuming that it is placed on a panel board of a Wireless apparatus, the handle 23 is turned until the desirable amount of resistance is cut in which is indicated by the position of the bar 4l in the groove 40, and then the current passing through the rheostat is measured by the number which appears under the handle 28 so that the operator can not only regulate it, Ibut Will know exactly what he is doing when so regulating it Without the use of any additional instrument.

' While I have shown and `described one embodiment of my invention, it is obvious that it is not restricted thereto but that it is broad enough to cover all structures that come Within the scope of the annexed claims.

Having-thus described my invention, what I claim 1s:

q1. A rheostat provided with a spool with a double thread thereon, two Wires, one in more or less resistance may be cut in or out of circuit.

.according tothe resistance cut in or out of circuit.. Y

4. A dial and means for supporting the same, a spiral groove in said dial, a bar engaging. said dial and passing into said groove, 'a handle, means on said handle for guiding said bar, a. spindle connected to said handle, a spool mounted in fixed relation to said dial, a double thread on said spool, two wires, one ineach thread, means for elec ltrically connecting the wires in adjacent threads and means for mounting the same from the spindle so that said Wires will be connected according to the Way the spindle is turned, whereby more or less resistance may 'be thrown in or out of circuit and the amount of resistance .so ,thrown in or out Will be indicated by the location of the bar.

5. A rheostat provided with a. dial having a spiral groove, numbers indicating resistance on said dial and` adjacent to the couvolutions of said groove, a handle, a bar connecting said groove and provided with current indicating devices and means for cutting resistance in or out' of circuit so as to correspond with the resistance numerals of the dial. z In testimony whereof, l have hereunto set my hand this l2 da of July, 1922.

,Y {DAUL HARRIS. 

